JPH04145201A - Pneumatic drive unit - Google Patents

Abstract

PURPOSE:To perform positioning into an optional target position speedily with high accuracy by driving control valves formed of parallel-connected on-off valves through control drive parts by each valve opening signal computed from air pressure and the present and target positions of an action part so as to control the inflow/outflow of air to/from the air chambers of an actuator. CONSTITUTION:The inflow/exhaust of air supplied from compressed air source 4 to/from the air chambers, divided by a vane, of an oscillating cylinder 1 is controlled by control valves 5a-5d formed of parallel-connected on-off valves and driven by control drive parts 9a-9d. The pressure to each air chamber is detected by pressure sensors 6a, 6b, and the position of the vane is detected by a position sensor 7. These detection signals and a target position signal are inputted into the opening quantity control part 10a of an action control part 10-1 for computation, and the deviation of the vane to the target position is outputted to the control drive parts 9a-9c from an opening signal output part 10e through an opening quantity command valve judging part 10b, an on-off valve selecting part 10c and an opening valve determining part 10d. Optional positioning can thereby be performed speedily with high accuracy.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a pneumatic drive device that operates using a compressed air source as a drive source.・Easy to reduce weight. Transmission from the drive source to the moving parts can be done easily and freely using piping. Furthermore, it is inexpensive, does not pollute the environment, and takes advantage of its advantages such as being able to hold force and store it as pressure energy. Although it is widely used in the industrial field, it has been possible to position only one or a few points using a mechanical stopper. Proportional control valves, which have the function of changing the opening area of the valve part according to a command value, have made progress.It has become possible to control the pressure inside the air chamber, and it has become possible to position it at any position. By driving an on-off valve under pulse width modulation (hereinafter referred to as PWM) control instead of a proportional control valve, it has become possible to position the L at any position. An example of a drive device will be explained. Fig. 20 shows an example of a conventional pneumatic drive device. In Fig. 20, 1 is a pneumatic swing cylinder;
4 is compressed air pressure i 6a, 6b is pressure sensor, 7
is a position sensor, 8 is a negative 115a, 15b is a proportional control valve, 19a, 19b is a proportional control valve controller, 20
The operation control 120a is the opening amount command value, and 20d is the opening amount determination! 20e is an aperture signal output section.

The operation of the conventional pneumatic drive device configured as described above will be explained below, but first, the operation control section 2 (
Ndai A control system that suppresses the influence of air compressibility and seal friction on the positioning operation of the pneumatic drive system is created through state feedback control of the pneumatic drive system including the cylinder 1 and load 8 and integral control of position deviation. The operation control unit 20 calculates the opening area of the proportional control valve by inputting the speed signal and the operation target position determined by the difference between the pressure signal of the pressure sensor 6a16b, the position signal of the position sensor 7, and the position signal. By outputting the opening area signal to the proportional control valve controllers 19a, 19b, the opening areas of the proportional control valves 15a, 15b can be changed, and high precision positioning of the operating part in the pneumatic drive device can be achieved at any position. (For example, Noritsugu et al., “Optimal control of pneumatic servo systems considering the operation delay of electro-pneumatic control valves,” Journal of the Society of Instrument and Control Engineers Vol. 24, No. 5, May 1988, p. 58) Next Conventional pneumatic pressure Another example of the drive device will be explained. Fig. 21 shows another example of the conventional pneumatic drive device. In Fig. 21, 1 is a pneumatic swing cylinder, 4 is a compressed pneumatic woodcutter 6a, 6b pressure sensor, 7 is a position sensor, 8 is a negative 125a-25d is an on-off valve,
29a to 29d are PWM control drives a 30 is an operation control ff1L 30a is an opening amount control @ 30d is an opening amount control section 30e is an opening signal output section Same as the example of the conventional pneumatic drive device described above. A control system is constructed that suppresses the effects of air compressibility and seal friction through state feedback control and integral control of position deviation.The on-off valve is controlled by outputting the obtained opening time signal to the PWM control drive unit. 25a-25
d can be driven by PWM to control the flow rate and achieve high precision positioning at any position in a pneumatic drive device. This shows still another example of the drive device. In Fig. 22, 1 is a pneumatic swing cylinder, 4 is a compressed air pressure i, and 5a to 5d are air cylinders each consisting of 11 on/off valves connected in parallel. valve; 6a, 6b are pressure sensors; 7 is a position sensor; 8
is negative i9a to 9d is control drive unit 40 is operation control @ bustling 40
a is the opening amount control s, 40d is the opening amount control section 40e
is an opening signal output section. Similar to the example of the conventional pneumatic drive device described above, the operation control section 40 suppresses the influence of compressibility of air and the influence of friction of the seal section through state feedback control and integral control of position deviation. By configuring a control system such as Even if accurate positioning is achieved, the problems that the invention attempts to solve cannot be solved.Introduction In the first conventional example, the proportional A voltage signal which is an opening area signal for directly driving the control valves 15a and 15b and a proportional control valve 15 corresponding to the voltage signal.
Fig. 23 is a valve characteristic diagram of the opening area of a and 15b, and in Fig. 23, vi is the voltage signal Si is the opening area.
sO indicates that the proportional control valve is fully closed, and LvO is the voltage signal at that time. In FIG. 23, it corresponds to the opening area command value calculated by the opening amount control unit 20a of the operation control unit 20. When outputting a voltage signal to the control drive unit, if the opening area command value increases, the voltage signal is input from vO to v i-1, v i-2, and the valve characteristics are linear and the accurate opening area S i
-1, s i-2 could be obtained. However, next time the opening area command value decreases and the voltage signal v i-3 is input, if the valve characteristics are linear, the opening area will be 5 i-
3, but since the valve characteristics are nonlinear, the opening area is s
In the first conventional example, a force exchange using a proportional control valve to change the opening area.In this case, the relationship between the opening amount signal and the flow rate through the proportional control valve is However, due to the presence of hysteresis, the flow characteristics become nonlinear, making it difficult to control the flow rate accurately, and the positioning time becomes long.
As shown in the figure, if the proportional control valve is abnormal, complete fN, t
In the second conventional example, instead of changing the opening area, the opening time of the on-off valve was changed by PWM control. This achieves miniaturization while realizing the function of a proportional control valve. However, in this case, when the opening amount signal is small and the valve opening time is short, the opening amount signal and the on/off valve may not be compatible due to factors such as valve operation delay. Since the relationship between the flow rates is not constant and is non-linear, it becomes difficult to control minute flow rates and the positioning time becomes long. In the third conventional example (A), the PW of the on-off valve
The problem with the M drive is to use a large number of on-off valves (\OpenL) to change the J area and control the minute flow rate. The number of on/off valves is controlled5, but as the number of on/off valves increases,
-) The problem that the control drive parts 9a to 9d and the operation control part 10 are complicated is solved. :) The input signal ui is the valve characteristic of a pneumatic valve consisting of 11 menoff valves.
Figure 24 () shows the valve characteristics when the valve is normal, and Figure 24 (b) shows the valve characteristics when one valve is abnormal. From Figure 24, 11
In a pneumatic valve made up of several on-off valves, if even one on-off valve is abnormal, it becomes difficult to control the flow rate only in the part driven by that on-off valve.1 It becomes difficult to control the flow rate accurately. In view of the above-mentioned problems, the present invention eliminates the influence of the non-linear part on the valve characteristics of the air valve (7) and performs accurate flow rate control. By simplifying the parts corresponding to the control drive parts 9a to 9d and the operation control part 40 in FIG. 22, and by providing an auxiliary function in case of an abnormality, a high-speed, high-precision positioning method for marking an arbitrary target position can be achieved. The object of the present invention is to provide a pneumatic drive device that easily and always accurately realizes the following operations. H is a pneumatic actuator having first and second air chambers in which air flows in or out (pressure changes) and a movable operating section located between the air chambers, and the operating section. A first air valve consisting of at least two or more N1 on/off valves connected in parallel that allows air to flow into the first air chamber divided by the air flow chamber, and air flows out from the first air chamber. a second air valve consisting of at least two or more 〇N2i on/off valves connected in parallel, and at least two or more N3 valves connected in parallel to flow air into the second air chamber; a third air valve consisting of an on-off valve, and a fourth air valve consisting of at least two or more N4 on-off valves connected in parallel that discharge air from the second air chamber. and N1 air valves for controlling the flow rate by controlling the opening [-] amount of each of the air valves in order to allow air to flow into or out of each of the air chamber groups. a first control drive having a valve drive;
a second control drive section having N2 valve drive sections for the second air valve;
a third control drive unit having 13 valve drive units; a fourth control drive unit having 5 to N4 valve drive units for the fourth air valve; and an operating state of the operating unit. a detection unit that detects the position and the respective pressures applied to the operating parts of the air chamber group; and output signals of the detection unit, which are the position of the operating unit, the respective pressures applied to the operating parts of the air chamber group, and a target operation. Input the target position of the operating section in the state 2
control necessary for the operating unit to move according to the target side f [state? Calculate the opening amount command value of the air valve (.7. The device is configured with an operation control section that outputs an opening signal for driving the air valve to the control drive section of each of the air valves. The present invention uses the above-described means to eliminate the influence of the nonlinear part in the valve characteristics of the air valve, simplify the control drive section and the operation control section, and provide an auxiliary function in the event of an abnormality, thereby controlling the flow rate. It is possible to easily and always accurately perform a high-speed, high-precision positioning operation for an arbitrary target position.

EXAMPLE The purpose of this example is to eliminate the influence of the nonlinear part on the valve characteristics of the pneumatic valve, and to eliminate the influence of the nonlinear part on the valve characteristics of the pneumatic valve. Fig. 1 is an overall view showing the configuration of a pneumatic drive device in an embodiment of the present invention.4 In Fig. 1, 1 is An oscillating cylinder having an air chamber, 4 compressed air lines 5a, 5b, 5e, and 5d each having an opening area in a geometric progression with a common ratio of 2 for allowing air to flow in or out from the air chamber 11 6a and 6b are pressure sensors that detect the internal pressure of the air chamber, 7 is a position sensor that detects the position of the operating part, and 8 is a high-performance valve 9a and 9b.
, 9c, 9d are air valves 5a, 5b, respectively.
The control drive @10-1 that drives 5c and 5d is motion control! 10a is the opening amount control ff1L; 10b is the opening amount command value judgment pulse; 10C is the on-off valve selection i; 10d is the opening valve determination expansion section; 10e is the opening signal output section; The operation will be explained using FIGS. 6 to 6. First, FIG. 2 is a detailed explanatory diagram of the pneumatically driven oscillating cylinder 1 in FIG. are vanes that can move inside the cylinder 1 while maintaining airtightness; 3a, 3b are air chambers divided by the vanes 2; 4 are compressed air handles 5a, 5b, 5c;
5d is an air valve for letting air flow into or out of the air chambers 3a and 3b, respectively; 6a and 6b are pressure sensors for detecting the internal pressure of the air chambers 3a and 3b, respectively; FIG. 3 is the same as that in FIG. Operation control section 10
In FIG. 3, which is a detailed explanatory diagram of the opening amount control section 10a, 21 is the target position [22 is the position 23a, 23b]
is the internal pressure 24 of the air chambers 3a and 3b is the reference pressure 11
is an integrator 12 is a differentiator 13a, 13b, 13
c, 13d, 14aS 14b, 14 c
, 14d, 14e, and 14f are amplifiers. The outputs of 13a, 13b, and 13c are feedback components of the position deviation of the vane 2 relative to the target position, the speed of the vane 2, and the pressure deviation from the reference pressure of the air chambers 3a and 3b, respectively, and these are the feedback components of the oscillating cylinder 1,
The air chambers 3a and 3b constitute a state feedback control system for the pneumatic drive system including the vanes 2 and loads 8.
pl, the moment of inertia of p & vane 2 and the entire load is J, the coefficient of viscous friction is b, the pressure receiving area of the vane is A, the center radius of the outer radius and inner radius of the pressure receiving part of the vane is rO, If the amount of rotational displacement of the vane is θ, then Jθ +
The relationship bθ = A-r(1(pi-p2) (1) holds true.

Here, θ represents the second differential of θ with respect to time, and θ represents the single differential of θ with respect to time. Pressure pi (i=1 or 2
) and the opening area 5i of the air valve (when i=1 or 2, 1 indicates the air chamber 3a, and 2 indicates the air chamber 3b), the relationship between the upstream pressure and downstream pressure of the air valve is as follows. Assuming that there is a sufficient difference between
2 with respect to time, ps is the supply pressure fi k
l and k2 are constants related to the vane shape, temperature, etc.
At this time, the expanded state equation 4, δp, which includes the state variable of the integrator to eliminate the friction of this pneumatic drive device
= pl−p2 (4) δ s
= sl -52, it can be obtained by the formula x=[z θ δ δplT, where X is the one-time derivative of When the state feedback shown in Fig. 3 is performed based on the theory, the input δS (δs = kp・(θd−θ)−kv・θ+ki
-2kpr・δp(7) where θd is the target trajectory kp of the rotational displacement amount θ of the operating part,
kVSkpr are the state feedback gains 13a, 13b, and 13c of the pneumatic drive system. Through this state feedback control, it is possible to suppress the influence of air compressibility on positioning operation and realize positioning operation at any position of the operating part. In addition, ki is an integral gain of 13d, and even though the output of 13d amplifies the integral value Z of the positional deviation and outputs it, this integral control of the positional deviation suppresses the influence of friction on the positioning operation, and allows arbitrary control of the operating part. Here, the opening area of each air valve is pi-p2 = (pi-pO) - (p2-pO)
= δppl+p2=2 ・ pO sl-s2= δ S sl+s2= 0 In this case, 14a, 14b, 14c, 1
The amplification factors of 4 d, 14 e, and 14 f are all 0.
．． 5Team SL and S2 indicate inflow if positive value and outflow if negative value.

Further, FIG. 4 is a detailed explanatory diagram of the air valve 5a in FIG. 1. For the purpose of this embodiment, each air valve 5a,
5b, 5c, 5d +& 1 connected in parallel as shown in Figure 4, forming a geometric progression with an opening area of common ratio 2.
Even if it is composed of a single on-off valve, the valve characteristics of an air valve constructed by connecting in parallel 11 on-off valves whose opening areas are a geometric progression with a common ratio of 2 are shown in Figure 5. If the minimum opening area of an on-off valve is sit, then the opening area from sil to 2047・sil can be created digitally with the resolution sil, and the valve characteristics can be linearized, where 4ui is the input signal and Si is the opening area. Yes (the same applies below).

Now, the opening amount command value determining section 10b judges whether the opening area command value sit<255.sil calculated by the opening amount control section 10a is larger or smaller than the opening area command value sit<255.sil.
J (a), (b)L On-off valve selection section 10c
The on-off valve selection unit 10c determines the valve characteristics of the on-off valve group selected by From 5i
By selecting to drive eight on-off valves up to 8 (128·5 it), the valve characteristics are linearized with a resolution sil, and when si > 255·sil, the range is changed as shown in Fig. 6(b). s i4 (8・s il) to 5ill (1024
By selecting to drive eight on-off valves up to 5il), it is possible to linearize the valve characteristics at a resolution of si4 and reduce the number of on-off valves used at one time. In this step, the on/off valve to be driven is determined from among the eight on/off valves selected by the on/off valve selection unit 10c according to the opening area command value, and the opening area signal is sent from the opening signal output unit 10e to the control drive units 9a to 9d. Output.

Here, FIG. 7 is a detailed view of the control drive section 9a, and as shown in FIG. 7, the control drive section includes eight valve drive sections 9a-
1 to 9a-8 and 11 on/off valves 5a-1 to 5a-1
1, 8 consecutive on/off valves 5a-1 to 5a-8 or 5a-4 to 5a-11 are switched according to the command.
Alternatively, it has a connecting valve drive part distribution part 9a-12, and connects the on-off valve and the valve drive part driven by the valve drive part part 9a-12 according to the opening area signal to drive the on-off valve. Although the flow rate is controlled according to the opening area, there are cases where the opening area cannot be accurately controlled due to nonlinearity of the valve characteristics, or when the control drive unit and operation control unit are complicated. Consists of 11 on-off valves connected in parallel whose area is a geometric progression with a common ratio of 2. By selecting the on-off valve that is driven according to the opening area of the air valve, it is possible to digitally operate with a small number of on-off valves. By linearizing the valve characteristics, it is possible to accurately and easily control the opening area of the air valve, that is, the flow rate can be controlled accurately and easily.As described above, in this embodiment, the air valves 5a to 5d are arranged in parallel whose opening areas are a geometric progression with a common ratio of 2. 11 connected to
The operation control section 10-1 includes an opening amount command value judgment section 10. By selecting on-off valves to be driven according to the opening areas of the air valves 5a to 5d, in which the on-off valve selection unit 10c is installed, valve characteristics can be easily linearized digitally with a small number of on-off valves, and precision can be achieved. The second embodiment of the present invention will be described below with reference to the drawings, but the purpose of this embodiment is to Figure 8 shows that the present invention allows the flow rate to be controlled accurately at all times by providing an auxiliary function in the event of an abnormality in the air valve. In FIG. 8, 1 is a swing type cylinder having an air chamber, 4 is compressed air fL, 5a, 5b, 5c,
5d is an air valve consisting of 11 on/off valves whose respective opening areas form a geometric progression with a common ratio of 2 for allowing air to flow in or out from the air chamber; 6a; 6;
b is a pressure sensor that detects the internal pressure of the air chamber,
7 is a position sensor that detects the position of the operating part, 8 is a good sensor
9a, 9b, 9c, and 9d are control drives ff1 that drive the air valves 5a, 5b, 5c, and 5d, respectively.
L 10-2 is an operation control section 10a is an opening amount control section
10d is the opening valve determination ff1L10e is the opening signal output unit, which is the same as the configuration shown in Fig. 1. What is different from Fig. 1 is that the 11 opening areas connected in parallel are equal to each other with a common ratio of 2. Air valves 5a, 5b, 5c are composed of on-off valves that are ratio series.

5d, an operation control section 10-2, an auxiliary air valve consisting of 11 on-off valves each connected in parallel and whose opening areas are a geometric progression with a common ratio of 2; For the purpose of this embodiment, the operation of the pneumatic drive device configured as above in that it is provided with the opening auxiliary valve determining section Log will be described below using FIGS. 8 to 10. In Figure 8, the air valves 5a to 5d are composed of 11 on/off valves connected in parallel whose opening areas are a geometric progression with a common ratio of 2.
An auxiliary air valve consisting of 11 on-off valves connected in parallel with the same opening area as the on-off valve constituting the on-off valve is added. 11 connected on/off valves 5al-1 to 5al-
This is a configuration diagram of an air valve 5a in which an auxiliary air valve 5a2 consisting of 11 on-off valves 5a2-1 to 5a2-11 connected in parallel is added to a main air valve 5a1-11. air valve 5 b.

Although 5c and 5c are similarly configured, FIG. 10 shows 11 on/off valves 5a2-1 to 5a2-1 connected in parallel.
Based on the valve characteristics of the auxiliary air valve 5a2 constituted by 5a2-11, the opening valve determining unit 10d determines the on/off valve to be driven according to the opening area command value si calculated by the opening amount control unit 10a. When the valve operation inspection unit 10f detects an on-off valve that cannot be driven, that is, when a flow rate that cannot be controlled due to the valve characteristics occurs, the auxiliary air valve 5a2 is added in parallel by the opening auxiliary valve determining unit 10g as a substitute for the on-off valve that cannot be driven. On-off valve 5a that constitutes
The on/off valve to be driven is determined from among 2-1 to 5a2-11, and the control drive unit 9a to 5a is determined from the opening signal output unit 10e.
An opening area signal is output to the valve drive unit of the on-off valve to be driven included in FIG. 1-5a2-11
By controlling the auxiliary air valves 5a2 connected in parallel, the valve characteristics can always be linearized.
As described above, according to this embodiment, the air valves can be controlled accurately at all times. It is composed of an auxiliary air valve consisting of 11 on/off valves in a ratio sequence, and an on/off valve operation inspection section 1 is installed in the operation control section 10-2.
0f and the opening auxiliary valve determining section 10g are installed, the air valves 5a~
If the on/off valve that makes up part 5d cannot be driven and an uncontrollable flow rate occurs, the auxiliary air valve can linearize the valve characteristics and always accurately control the flow rate. Although the third embodiment of the present invention will be described below with reference to the drawings, the purpose of this embodiment is to eliminate the influence of the nonlinear part on the valve characteristics of the air valve. By providing an auxiliary function in case the air valve is abnormal, the flow rate can be controlled accurately at all times. Figure 11 is an overall diagram showing the configuration of a pneumatic drive device showing a third embodiment of the present invention. However, in FIG. 11, 1 is an oscillating cylinder having an air chamber, and 4 is a compressed air source 5a, 5b, 5c.

5d are air valves 6a and 6b each consisting of an on/off valve for letting air flow in or out from the air chamber;
7 are pressure sensors that detect the internal pressure of the air chamber, respectively;
is a position sensor that detects the position of the operating part, 8 is a negative 'K
9a, 9b, 9c, and 9d are control drives K for driving the air valves 5a, 5b, 5c, and 5d, respectively; 10-3 is an operation control section; and 10a is an opening amount control section; the above structure is the same as that shown in FIG. What is different from Figure 1 are air valves 5a, 5b, and 5C15.
The operation control unit 10 is composed of 3000 on/off valves connected in parallel, each having the same opening area.
-3 +Q The pneumatic drive device configured as above in that it is provided with the on-off valve operation inspection section 10f, the opening aperture calculation section 10h, and the opening signal distribution section 10i is shown in Figs. 11 to 14 below. For the purpose of this embodiment, which describes its operation using a
2 Figure 4; La2O Air valve 5a composed of 2 on-off valves is composed of 953 on-off valves connected in parallel to main air valve 5al composed of 2047 on-off valves connected in parallel. This is a configuration diagram of the air valve showing that it is configured by parallel connection with the auxiliary air valve 5a2.
Even though the other air valves 5b, 5c, and 5d are configured in the same way, Fig. 13 shows the valve characteristics of up to 2047 main air valves of the air valves made up of 3000 on/off valves, and (a) shows the valve characteristics when the valves are Valve characteristics t when the valve is normal; (b) shows the valve characteristics when the valve is abnormal; FIG. 14 shows the valve characteristics of the air valves including the auxiliary air valve. The number of on-off valves to be driven is determined by the opening number calculation unit 10h according to the calculated opening area command value si, and when the on-off valve operation inspection unit 10f detects an on-off valve that cannot be driven among the main air valves, that is, the valve When a flow rate that cannot be controlled due to the characteristics occurs,
From Figure 13, in the main air valve consisting of 2047 on/off valves connected in parallel with the same opening area, it is not possible to control the flow rate only in the part driven by the on/off valve. The signal distribution unit 10i decides to drive the on-off valves among the 953 auxiliary air valves connected in parallel instead of the on-off valves among the main air valves that cannot be driven, and is included in the control drive units 9a to 9d. By outputting an opening area signal to the valve drive part of the on-off valve to be driven, as shown in Figure 14, the valve characteristics can always be linearized and the flow rate can always be accurately controlled. According to this embodiment, 95 air valves connected in parallel have the same opening area as the main air valve consisting of 2047 on-off valves, which have the same opening area.
Consists of an auxiliary air valve consisting of three on/off valves.
The on/off valve operation inspection section 10f, the opening number calculation section 10h, and the opening signal distribution section 10i are installed in the operation control section 1°-3.If the on/off valve that constitutes the main air valve cannot be driven and an uncontrollable flow rate occurs, k Auxiliary It is possible to linearize the valve characteristics as an air valve and always accurately control the flow rate by using the air valve.It is also possible to easily realize high-speed, high-precision positioning operation for any target position.The following is a fourth embodiment of the present invention. An example will be explained with reference to the drawings, but the purpose of this example is to eliminate the influence of the nonlinear part on the valve characteristics of the air valve, and to provide an auxiliary function in case the air valve is abnormal, so as to maintain the flow rate at all times. FIG. 15 is an overall view showing the configuration of a pneumatic drive device according to a fourth embodiment of the present invention. In FIG. 15, 1 is an oscillating cylinder having an air chamber; 4 is compressed air #5a, 5b, 5c, 5d is air composed of 11 on-off valves whose respective opening areas are a geometric progression with a common ratio of 2 to allow air to flow in or out from the air chamber valves, 6a and 6b are pressure sensors that detect the internal pressure of the air chamber, 7 is a position sensor that detects the position of the operating part, 8 is a negative fi 9a,
9b, 9c, and 9d are air valves 5a, 5b, and 5, respectively.
10-4 is an operation control unit, 10a is an opening amount control unit, and 10d is a Sekiguchi valve determining unit.
e is an aperture signal output section - the above is the same as the configuration shown in Fig. 1; Q: This is a book that explains the operation of the pneumatic drive device configured as described above in that it is provided with the on-off valve operation inspection section 10f and the opening valve change section 10j, using FIGS. 15 and 16. For the purpose of the embodiment, the opening valve determining unit 10d determines the on/off valve to be driven according to the opening area command value si calculated by the opening amount control unit 10a.On/off valve operation inspection unit 10
When an on-off valve that cannot be driven is detected by f, that is, when an on-off valve cannot be driven due to the valve characteristics and an uncontrollable flow rate occurs, the opening valve changing unit 10j changes the uncontrollable flow rate among the 11 on-off valves. Controlled only by normal on/off valves Figure 16 1
This is the valve characteristic corrected by the opening valve changing unit 10j,
It is possible to always reduce the nonlinearity of the valve characteristics, but also specifically (with a minimum opening area of 81 and a maximum opening area of 8
11=1024・Sl, and the air valve is 2047
・Even if the area up to SL can be opened, the opening amount control section 1
In order to open an opening area of 25·Sl in the opening valve determination unit 10d according to the opening area command value si calculated in step 0a, an on-off valve with an opening area of 81.54=8·Sl and 55=16·Sl is set. If the on-off valve operation inspection section 10f tests that the on-off valve with an opening area of 84 = 8 SL is abnormal, the opening area as an air valve will be 17 SL. Among the 10 on/off valves other than 84 in the changing unit 10j, the valves S1, S2, S3 . S
By selecting to drive the four on-off valves of No. 5 and opening the opening area of 23.Sl as air valves,
The opening valve determining unit 10d selects the combination of on/off valves closest to the opening area 25·Sl determined, and the opening signal output unit 10e sends the on/off valve combination included in the control driving units 9a to 9d to the valve drive unit of the on/off valve to be driven. By outputting the opening area signal, it is possible to control the flow rate more accurately when the on-off valve is not driven.As described above, according to this embodiment, the opening area of the air valve is 2.
The operation control unit 10-4 includes an on-off valve operation inspection unit 10.
If an on/off valve that constitutes an air valve cannot be driven and an uncontrollable flow rate occurs, the remaining on/off valves can linearize the valve characteristics and accurately control the flow rate. A fifth embodiment of the present invention will be described below with reference to the drawings. By eliminating the influence of the non-linear part in & In FIG. 17, which is an overall view showing the configuration of the pneumatic drive device, l is a swinging cylinder having an air chamber, 4 is a compressed air handle 5a, 5b, 5c, and 5d for allowing air to flow in or out from the air chamber. The air valve is composed of 11 on/off valves whose respective opening areas are a geometric progression with a common ratio of 2. 6a and 6b are pressure sensors that detect the internal pressure of the air chamber, and 7 is an operating part. A position sensor that detects the position of 8 is negative J9a, 9b,
9c and 9d are air valves 5a, 5b, and 5c, respectively.
, 5d 10-5 is the operation control section 10a is the opening amount control section 10d is the opening valve determination 110e
1 is an opening signal output section, which has the same configuration as that shown in FIG. 1, but is different from that shown in FIG.
Regarding the pneumatic drive device configured as described above, for the purpose of this embodiment, whose operation will be explained below using FIGS. 17 to 19, it is assumed that any one of the pneumatic valves is If there is an abnormality, the two air valves for inflow and outflow are driven at the same time, and a function is added to create an accurate flow rate based on the flow rate difference between the two air valves.
With the valve characteristics of each of the two air valves shown in FIG. When an on-off valve to be driven is determined in step 10d, and an on-off valve that cannot be driven is detected in on-off valve operation inspection section 10f, that is, when a flow rate that cannot be controlled due to the valve characteristics occurs, two air chambers, one for inflow and one for outflow, are determined per air chamber. The opening valve differential operation instruction section 10k simultaneously controls the two air valves as shown in FIG. ), the other air valve is driven with the valve characteristics as shown in (a), and the control drive parts 9a to 9 are transmitted from the opening signal output part 10e.
By outputting an opening area signal to the valve drive unit of the on-off valve to be driven included in d, the difference in flow rate based on the opening area of the two air valves becomes the actual flow rate based on the opening area, and the 19th
As shown in the figure, the valve characteristics can always be linearized, and the flow rate can always be controlled accurately.According to this embodiment, the air valve opening area is a geometric progression with a common ratio of 2. The operation control unit 10-5 is equipped with an on-off valve operation inspection unit 10f and an opening valve differential operation instruction unit 10k. If an uncontrollable flow rate occurs, by driving the two air valves for inflow and outflow simultaneously in a region where each valve characteristic is linear, the valve characteristics can be linearized by the difference in flow rate based on the opening area. , it is possible to always accurately control the flow rate, and it is also possible to easily realize high-speed, high-precision positioning operation for any target position. Although we used a control law based on feedback of the integral value, it is not necessarily limited to this control law. Although an oscillating cylinder was used in the embodiment, the same effect can be obtained with a pneumatic actuator driven by a pressure difference between air chambers, such as a direct-acting cylinder. In addition, in the second embodiment, each auxiliary air valve is
It is made up of 11 on-off valves in total, and the opening area is the same as the on-off valves that make up the air valve.The number of on-off valves may be different for each auxiliary air valve, or the number of on-off valves that make up the air valve is the same. The on/off valves may have different opening areas.Also, in the third embodiment, each air valve is made up of 3000 on/off valves, but each air valve has a different number of on/off valves. Also, in the third embodiment, each main air valve has 2047 on/off valves, and all auxiliary air valves have 95.
The number of on-off valves may be different for each main air valve, and the number of on-off valves may be different for each auxiliary air valve.11% In addition, in the fourth embodiment, the fourth on-off valve may be any number of on-off valves, or it may be applied to cases where multiple on-off valves are abnormal. Although the opening area of the air valve was controlled in the embodiment, the same effect can be obtained even if the opening time of the air valve is controlled. a pneumatic actuator having first and second air chambers and a movable operating part located between the air chambers; and a pneumatic actuator connected in parallel that allows air to flow into the first air chamber divided by the operating part. A first air valve composed of at least two or more N1 on-off valves, and at least two or more N2 on-off valves connected in parallel that discharge air from the first air chamber. a second air valve;
a third air valve consisting of at least two or more N3 on-off valves connected in parallel that allows air to flow into the second air chamber; a fourth air valve composed of at least two or more N4 on-off valves, and controlling the opening amount of each of the air valves in order to allow air to flow into or flow into each of the air chamber groups. said first controlling the flow rate by
a first control drive having N1 valve drives for said second air valve; a second control drive having N2 valve drives for said second air valve; and said third control drive having N2 valve drives for said second air valve. a third control drive having N3 valve drives for said fourth air valve; a fourth control drive having N4 valve drives for said fourth air valve; and said operating part. a detection section that detects the position of the operating state of the air chamber group and the pressure applied to the operating section of the air chamber group; and an output signal of the detection section that detects the position of the operating section and the respective pressure applied to the operating section of the air chamber group. calculates an opening amount command value of the air valve, which is a control amount necessary for the operating section to move according to the target operating state, by inputting the pressure difference of and the target position of the operating section that is the target operating state; By providing an operation control unit that outputs an opening signal for driving the valve to the control drive unit of each of the air valves, the valve characteristics of the air valve are always linearized.
Q: By simplifying the operation control unit and control drive unit, and by providing an auxiliary function when an abnormality occurs in the on/off valve that makes up the air valve, flow rate can be controlled easily and accurately at all times, allowing high-speed height control to any target position. It becomes possible to easily realize accurate positioning operation.

[Brief explanation of the drawing]

Fig. 1 shows the overall configuration of the pneumatic drive device according to the first embodiment of the present invention; Fig. 2 shows the pneumatic circuit including the oscillating cylinder shown in Fig. 1; 4 is a detailed explanation of the opening amount control section in the operation control section. FIG. 4 is a detailed explanation of the air valve shown in FIG. 1. FIG. 6th
Figure 7 shows a detailed explanation of the control drive unit shown in Figure 1 @ Figure 8 shows a second embodiment of the present invention Fig. 9 shows the configuration of the pneumatic valve to which the auxiliary air valve is added in the second embodiment. Fig. 10 shows the valve characteristics of the auxiliary air valve in the second embodiment. Figure 12 shows the configuration of the pneumatic valve in the third embodiment of the present invention. Figure 13 shows the configuration of the pneumatic valve in the third embodiment. Figure 13 shows the configuration of the pneumatic valve in the third embodiment. Fig. 14 is a valve characteristic diagram of an air valve constituted by a valve. Fig. 14 is a valve characteristic diagram of an air valve having a main air valve and an auxiliary air valve in the third embodiment.
Figure 16 shows the overall configuration of a pneumatic drive device according to a fourth embodiment of the present invention. Figure 16 is a valve characteristic diagram of a pneumatic valve having a Sekiguchi valve changing section according to the fourth embodiment. Fig. 18 is a valve characteristic diagram of each pneumatic valve that operates differentially in the fifth embodiment. Fig. 19 shows the differential operation in the fifth embodiment. Valve characteristic diagram of a pneumatic valve with an indicator part 2
Figure 0 shows the overall configuration of an example of a conventional pneumatic drive device.
Figure 21 shows the overall configuration of another example of a conventional pneumatic drive device 1 Figure 22 shows the overall configuration of yet another example of a conventional pneumatic drive device @ Figure 23 shows the configuration of a proportional control valve in the conventional example Valve characteristic diagram Figure 24 is a valve characteristic diagram of a pneumatic valve constituted by an on-off valve in a conventional example.
2... Vane (operating part), 3a, 3b... Air block 4... Compressed air holder 5a, 5b, 5c, 5d...
・Air valve, 5a-1 to 5a-11...on/off valve,
5al, 5bl, 5cl, 5dl --- Main air sign
5a2.5b2.5c2.5d2---Auxiliary air valve, 5
al-1 to 5al-11... Main air valve on/off valve, 5a2-1 to 5a2-11... Auxiliary air valve on/off valve, 6a, 6b... Pressure sensor, 7... Position sensor, 8...Yoshino 9a, 9b, 9c, 9d...
Control drive! 9al~9a-8...Valve drive clothing 9a-12
, 9b-12, 9cm12, 9d-12... Valve-driven distribution barrel 10-1 to 10-5... Operation control @1loa.
...Opening amount control 13 10b...Opening amount command value judgment K
10c...On/off valve selection K 10d...Opening valve determination a 10e...Opening signal output K 10f・
・・On/off valve operation test ff15-10g・Opening auxiliary valve determination 10h・Opening number calculation clothes 10i・Opening signal distribution ff1L10J・Opening valve change ff1L
10k...Name of the agent responsible for instructing Sekiguchi valve differential operation Patent attorney Akira Okaji and two others Fig. ) [bl fig.
□h@Si1in〉Yu゛(9 sail Ti-1 Kuna Enita) ji# [Ki] JF. Air-cutting pressure force C, ten faces, one load, 11 sui-p19 section, 11 parts, closing part, 46, gel part, part 12, Figure 5α-9 air valve 5a/ - Main 9 air valve exchange 2- Supplement II Power empty valve Fig. 16 Fig. 18 Fig. 11> Fig. 19 Fig. 20 Fig. 21 Fig. 22 Fig. 23

Claims (1)

[Scope of Claims] (1) A pneumatic actuator having first and second air chambers into which air flows in or out and whose pressure changes, and a movable operating section located between the air chambers, and the operating section. A first air valve composed of at least two or more N1 on/off valves connected in parallel, which allows air to flow into the first air chamber divided by the air chamber, and a first air valve which flows out the air from the first air chamber. a second air valve composed of at least two or more N2 on/off valves connected in parallel; and at least two or more N3 on/off valves connected in parallel that flow air into the second air chamber. a third air valve consisting of a valve; a fourth air valve consisting of at least two or more N4 on-off valves connected in parallel that discharge air from the second air chamber; 1 (1) for the first air valve that controls the flow rate by controlling the opening amount of each of the air valves in order to allow air to flow into or out of each of the chamber groups.
a first control drive section having N1≧K1) valve drive sections and a valve drive section connecting the valve drive section and the on-off valve to be driven; (
a second control drive section having N2≧K2) valve drive sections and the valve drive section connecting the valve drive section and the on-off valve to be driven; and the third air valve. K
a third control drive section having three (N3≧K3) valve drive sections and the valve drive section connecting the valve drive section and the on-off valve to be driven; In contrast, a fourth control drive section having K4 (N4≧K4) valve drive sections and the valve drive section distribution section that connects the valve drive section and the on-off valve to be driven; and an operation of the operation section. a detection section that detects the position of the operating section and the respective pressures applied to the operating section of the air chamber group, and output signals of the detection section that are the position of the operating section and the respective pressures applied to the operating section of the air chamber group; and calculates the opening amount command value of the air valve, which is a control amount necessary for the movement part to move according to the target operation state, by inputting the target position of the operation part that is the target operation state, and an operation control section that outputs an opening signal for driving to the control drive section of each of the air valves, and the operation control section controls the opening amount of each of the air valves determined according to the operation of the operation section. an opening amount command value determination unit that divides the valve opening amount into an arbitrary number of regions according to the size of the opening amount, and determines to which region among the arbitrary number of regions the opening amount command value belongs; The types of on-off valves to be driven for each region of the air valve are those in which the opening amounts of the individual on-off valves are continuous, and the number of on-off valves is two or more and all the on-off valves that make up the air valve are In the first air valve, the number of N1 on/off valves is determined according to the area to which the opening amount command value determined by the opening amount command value determining section belongs. The second air valve selects to drive only 2 or more and less than N1 on-off valves determined for each area, and in the second air valve, the opening amount command value determined by the opening amount command value determining section is selected. selects to drive only the on-off valves determined for each region among the N2 on-off valves, which have a value of 2 or more and less than the N2 value, according to the region to which the third air valve belongs; Selecting to drive only 2 or more and less than N3 on-off valves determined for each region among the N3 on-off valves according to the region to which the opening amount command value determined by the command value determining section belongs. , in the fourth air valve, two or more air valves are determined for each region among the N4 on-off valves according to the region to which the opening amount command value determined by the opening amount command value determining section belongs. an on-off valve selection unit that selects to drive only less than N4 on-off valves; and an opening valve that determines an on-off valve to be driven from among the on-off valves selected by the on-off valve selection unit according to the opening amount command value. a determining unit; and an opening signal output unit that outputs the opening signal to the valve driving unit and the valve driving portion distribution unit of the control driving unit of each of the air valves to be opened determined by the opening valve determining unit. A pneumatic drive device characterized by: (2) The first air valve has an individual valve element opening amount N1
The second air valve has N2 on-off valves each having a different valve element opening amount, and the third air valve has N3 on-off valves each having a different valve element opening amount. 2. The pneumatic drive device according to claim 1, wherein the fourth pneumatic valve has N4 on/off valves each having a different valve element opening amount. (3) The opening amounts of the valve elements of the first N1 on-off valves, the second N2 on-off valves, the third N3 on-off valves, and the fourth N4 on-off valves are at a common ratio of 2 (4) The pneumatic drive device according to claim 1, wherein the first air valve is a main air valve composed of N1 on-off valves, and M1 on-off valves. The second air valve has a main air valve composed of N2 on-off valves, an auxiliary air valve composed of M2 on-off valves, and a third air valve has an auxiliary air valve composed of M2 on-off valves. The valve has a main air valve consisting of N3 on-off valves and an auxiliary air valve consisting of M3 on-off valves, and the fourth air valve is a main air valve consisting of N4 on-off valves. and an auxiliary air valve composed of M4 on-off valves, and the first control drive section has M1 valve drive sections for the auxiliary air valves of the first air valve. , the second control drive has M2 valve drives for the auxiliary air valves of the second air valve, and the third control drive has M2 valve drives for the auxiliary air valves of the third air valve. The fourth control drive unit has M4 valve drive units for the auxiliary air valve of the fourth air valve, and the operation control unit has M3 valve drive units for the auxiliary air valve of the fourth air valve. , an on-off valve operation inspection unit that tests whether each of the on-off valves forming the main air valve of each of the air valves operates normally; and an on-off valve that is driven from among the on-off valves forming the auxiliary air valve. an opening auxiliary valve determining unit for determining the opening amount, and the opening valve determining unit determines an on-off valve to be driven from among the on-off valves constituting the main air valve of the air valve according to the opening amount command value;
When the determined on-off valve of the main air valve is determined to be normal by the on-off valve operation inspection section, the opening signal output section opens the opening determined by the opening valve determining section according to the opening amount command value. The opening signal of the air valve is output to the corresponding valve drive unit of each of the control drive units, and if the on/off valve operation inspection unit determines that the operation is abnormal, the on/off valve of the main air valve determined to be abnormal is output. An on-off valve to be driven as a substitute is determined by an opening auxiliary valve determining section from among the respective auxiliary air valves, and the opening signal output section is configured to open the on/off valve determined by the opening amount determining section and the opening auxiliary valve determining section. 2. The pneumatic drive device according to claim 1, wherein the opening signal of the pneumatic valve having the auxiliary pneumatic valve is outputted to a corresponding valve drive of each of the control drives. (5) The first air valves each have the same valve element opening amount L1
The second air valve has L2 on-off valves each having the same valve element opening amount, and the third air valve has L3 on-off valves each having the same valve element opening amount. The fourth air valve has L4 on-off valves each having the same valve element opening amount, and the first control drive section has L1 valve drive sections for the first air valve. and the second control drive has L2 valve drives for the second air valve, and the third control drive has L3 valve drives for the third air valve. a valve drive, the fourth control drive;
The fourth air valve has L4 valve drive units, and the operation control unit calculates the number of openings, which is the number of on/off valves to be driven in the air valve, according to the opening amount command value. an opening number calculation section, an on-off valve operation inspection section that inspects whether each of the on-off valves in the air valve operates normally, and an on-off valve operation inspection section that inspects whether the on-off valve operation is normal depending on the opening number. an opening signal distribution unit that selects an on-off valve to be opened from among the on-off valves selected and distributes the opening signal to a corresponding valve drive unit of the control drive unit of each of the selected on-off valves. The pneumatic drive device according to claim 1, characterized in that: (6) In the operation control unit, the opening valve determination unit determines an on-off valve to be driven in the air valve according to the opening amount command value, and the on-off valve of the determined air valve is checked by the on-off valve operation inspection unit. If it is determined to be normal, the opening signal output unit outputs an opening signal for the air valve to be opened determined by the opening valve determining unit to the corresponding valve drive unit of each control drive unit, and If even one of the on-off valves of the air valve is determined to be abnormal by the on-off valve operation inspection unit, the opening amount command value and the on-off valve are determined from among normal on-off valves other than the on-off valve determined to be abnormal. an opening valve changing unit that selects an on/off valve such that a difference between the valve element opening amount and the sum of opening amounts of valve elements of the valve is minimized; 2. The pneumatic drive device according to claim 1, wherein the opening signal is output to a corresponding valve drive section of each of the control drive sections. (7) In the operation control unit, the opening valve determination unit determines an on-off valve to be driven in the air valve according to the opening amount command value, and the on-off valve of the determined air valve is checked by the on-off valve operation inspection unit. If it is determined to be normal, the opening signal output section outputs an opening signal for the air valve to be opened determined by the opening valve determining section to the valve drive section of each control drive section, and If even one of the on-off valves of the valve is determined to be abnormal by the on-off valve operation inspection unit, the two air valves on the inflow side and the outflow side are simultaneously driven in a region where the opening amount can be controlled accurately, An opening valve differential operation instruction unit that selects an on/off valve to be driven according to the opening amount command value from the on/off valves of the two air valves so as to obtain the valve opening amount determined by the difference in the valve opening amount of the two air valves. , wherein the opening signal output section outputs an opening signal for the air valve to be opened selected by the opening valve differential operation instruction section to a corresponding valve driving section of each of the control driving sections. The pneumatic drive device according to claim 1. (8) The detection unit is a position, velocity and pressure detection unit that detects the position and velocity of the operating unit of the air chamber group and the respective pressures applied to the operating unit of the air chamber group, and the operation control unit is configured to detect the position, velocity, and pressure of the operating unit of the air chamber group. Calculates the opening amount command value necessary for the operating section to move according to the target operating state using the position and speed of the detection section and the difference between the respective pressures as input, and outputs an opening signal to each control drive section of the air valve. Claim 1 characterized in that
Pneumatic drive device as described. (9) The detection section is a speed pressure detection section that detects the speed of the operating section of the air chamber group and the respective pressures applied to the operating section of the air chamber group, and the operation control section is configured to detect the speed of the operating section of the air chamber group. Calculate the opening amount command value necessary for the operating section to move according to the target operating state by inputting the difference between the respective pressures and the target speed of the operating section that is the target operating state. 2. The pneumatic drive device according to claim 1, wherein the pneumatic drive device outputs an output to a control drive unit. (10) The valve opening amount of the air valve is the sum of the opening areas of the on-off valves that are open, and the opening amount command value is the opening area command value for the air valve, and the control drive unit 2. The pneumatic drive device according to claim 1, wherein the flow rate is controlled by controlling the number of pneumatic drive devices. (11) The valve opening amount of the air valve is the sum of the opening times of the on-off valves that are open, and the opening amount command value is the opening time command value for the air valve, and the control drive unit 2. The pneumatic drive device according to claim 1, wherein the flow rate is controlled by controlling the number of pneumatic drive devices.